Coherence (US, 2013)
Genre: sci fi psychological thriller
It's about a dinner party the night a comet is passing by Earth. Then, things get weird.
I didn't know this film existed until about 8 years after it was released. I think it's great. It's a cast of unknowns in a film with a fairly original plot. It will continue to build steam as a cult film.
My only recommendation is that you don't read up on it or watch trailers. Let the film tell its story.

